Inliners International Forums General Discussion Hi Performance Packard help

I have a Packard 327 straight 8 that I'm working on and trying desperetly to increase the performance of. I seem to run into a lot of brick walls in finding information or parts to make it a reality. I have a spare 288 that will be donating its higher compression head longer rods and solid cam and i have located a local man who can regrind the cam for me. I also have a Edmunds 2X2 intake for the engine and plan to modify a set of V8 Chevy headers to fit as the exhaust spacing is close. I feel these modifications will get me close to around 200 hp but it will be severely RPM limited and 60 year old stock parts (Rods) are sketchy at best. If anyone has any input on non stock parts or modification ideas I would love to hear them. I have considered going big bore on the engine ( I feel the stock stroke is more than enough) but the cylinders will only allow a 1/8 overbore at best, so would cutting the cylinders completely out of the engine and using large sleeves be an option or would it take all support out of the deck of the block? Thanks for any help.

I wouldn't forego any radical ideas like a big bore option.
The limiting factor is breathing, not bore size. Doing some aggressive porting is key to getting these L-heads engines to breathe, also installing larger valves is helpful too and unshrouding the valve pockets in the head.

Look at having the cam reground to a more performance oriented profile, this will compliment the porting also.

I will enclose a link to picture of a cutaway of one of these. It seems that water is pretty close to everything so any major porting would be limited (though I will still do the best I can. I have thought maybe setting the block up on a mill cutting the ports out and installing sleeves in the ports but I don't know if it will seal.
https://www.dropbox.com/s/ni9mb6iclwio86k/618_519043579c803.jpg

What is the engine going to be in? What are you going to use it for? How dependable does it need to be?
There is a a lakes modified out of Salt lake that runs a supercharged Packard 8. In 2008 we were parked at the end of mile 2 at Bonneville. Some guys in a late model Ford truck stopped and asked him how fast he was going when he passed them on the way out from Salt Lake that morning. He said he didn't know because the only gauge he didn't have was a speedometer. He said he was only turning 2000 rpm and had another gear to go. The Ford guys said they were doing a little better than 90 mph when he went by. That big Packard 8 didn't even know it was hooked to anything. Big old torquey straight motors don't need RPMs to do their work. The McColluch didn't hurt.

The biggest gains are going to be in the bowl area and with the installation of larger valves. I would focus on the areas that will yield the biggest gains and then go from there. Also, keep one thing in mind, that regardless of what you do to increase the power and performance, its still a flathead, and your only going to get so much out of it, so I would only focus on the tried and true methods for getting any gains. The cylinder head swap is a plus, its also the first step for those building the Straight 8 Pontiac's. Relieving the block is also beneficial, so I would add that to your "to do" list along with the porting and larger valves. You might also look at a turbo or supercharging it with an M90 centrifugal supercharger, it will add a bunch of power for little money.

Turbocharge it! Just 5 PSI will give it about 30% more tq.

It will be in the 52 Packard club coup it came in. I would like to street drive it and I plan to do so rather often, i wont say every day but a few times a week for sure. I am considering some form of forced induction. Turbo would be good, I have a 471 a real GMC one so it would have to be gone through or some form of paxton/ vortech supercharger. Fuel injection is another possibilith but I'm not 100% on that yet. I would like to get 300hp out of it (more if possible). Factory rating was around 150hp so I need to double the output and not blow it up. Thank you everyone for all the answers

Not without a blower.

I kinda figured. If I understand boost somewhere around 7-8 PSI will give roughly a 50% increase in power. so 200 naturally aspirated plus 7-8 PSI of boost would get me close to the 300+ mark. On this type of engine if i had to chose between turbo, GMC blower or centrifugal what would the pros and cons be of each be in reference to heat build up and strain on supporting parts (IE the belt on the 471 running off the snout of the crank not forged pistons to handle the boost. Also any guess on a source for mile long connecting rods? I know this is no 350 Chevy so off the shelf would be out of the question but possibly a Chevy or Ford 6? Or a reasonable price custom set?

Also I looked into the source of that lakester's aluminum head and the guy who made them doesn't anymore, which was bad news but I did find another source Empire Motors out of Texas. He makes an Edmunds replica but with a better combustion chamber design and it is thicker thus holding more water. The price is pretty steep, close to $3,000 would the investment be worth it over a 1953 iron head with a smaller combustion chamber than my 327? The part looks amazing but power for dollar (should I even be thinking about that? lol) would it be worth it?

If money were no object, then something like that would be tempting, but I would stick with the basics at first, until you got it running and determined it was going to be somewhat reliable, then you could swap the head at a later time. As for which type of forced induction to use, im sure they each can get you to your target, and since any one will require a complete fabrication of support components to install it, you just need to decide how much of the fab work you can do or don't want to do and go from there.

Mentally the turbo set up would be the easiest but I am not super familiar with supercharging in general to be honest. One thing that does concern me are the rods. They are crazy long (which to means mean prone to flexing) however they are forged but they have an oiling hole that runs from the big end to the piston pin. Packard guys seem to swear that it is essential to keep the engine from catastrophic failure but even with the tall cylinders I don't feel that it is and an aftermarket rod could be made to work. Any thoughts?

PS CNC-Dude love the signature!

Ha ha...thanks! The center oil hole design is identical to the GMC Jimmy rods, and works well to get pressurized oil to the wrist pins, and also sprays the underside of the piston crown to cool it. That can be a big bonus if using forced induction to help keep piston temps down. Getting a lighter weight piston if possible will help reduce strain on the rods, and could help offset the increased load you will be putting back on them with the turbo or blower. It would be nice if you could find some ARP quality rods bolts from another engine that you could swap into your rods. That would make me feel more comfortable than anything.

Is an aftermarket rod available for the GMC engine (I assume you mean the 302?) I would be much more comfortable With a forged piston and a billet rod to be honest lol Less weight and strain on the crank but then again most modern high performance engines have some sort of piston squirter. Down side being the Packard rods are every bit of 8.500 inches long so it would be a pretty custom set up. I am a fan of a strong bottom end (piston, rods, main studs, main girdle, ect) and it will leave me room to grow should I want to turn up the boost at a later date.

Have a feeling this will be a drawn out process to get the engine to its final conclusion and again thanks for the ideas and info.

There really isn't an "off the shelf" rod available for the GMC, or really any other of the older vintage engines. But custom is another matter, it just becomes a matter of how much you feel like spending to get a set.

Well the rough estimate I got from Arias on the pistons was about a grand, for rods to where I wouldn't have to worry about it I could go 2 grand but then again I don't know if that would cover it. If money were no object I would spring for a custom aftermarket rotating assembly. But the math as i'm seeing it brakes down like
$1000 pistons
$2000 rods
$1000 rebuild, gaskets bearings ect
$??? valves, springs
$200 cam regrind
$3000ish turbo/ supercharger system
and I'm sure much more than what I am expecting but that is over $7000 with just that so about a 10,000 budget would probably get me close.

Thought about the project more. Turbo with a blowthrough carb, any thoughts?

Plenty of people have done blow through carbs take a look at a guy called twisted 6 i think, he does a lot of blow through carbs i really want to see this engine go gets me pumped on my own project! Dont feel bad i heard in modern times on average for a full restore of a vehical it takes 30k and 6 years

On a up note sweet engine straight 8s are really bad a$$ propes to you

Maybey you can talk scott into forging custom parts for you;)

If I understand boost somewhere around 7-8 PSI will give roughly a 50% increase in power

Somehow, this idea keeps repeating.
No, adding 1/2 of atmospheric pressure doesn't increase power 50%. It also cannot calculate what other losses will occur:
1. power to drive the blower (yes, even a turbo has parasitic loss)
2. power lost through higher temperature

More information? Read my article here:
http://victorylibrary.com/mopar/blower.htm

Thanks for the article link very informative.

This is a project that you need to research throughly before you do anything. I suppose that this thread is part of that. Good start. You seem to be doing some at other sources as well. The toughest thing is to be honest with yourself about how this build will be used and build for that. You can spend a ton of money to build a powerful engine that you won't want to drive several times a week on the street.

If it were my project : #1. It would never get finished. #2. I'd build it using stock rods and custom forged pistons. At 8.5" you are not likely to find a better off the shelf rod. Yours can probably be helped a little. #3. I'd start with the stock head and see what can be gained with it. #4. I'd see what improvement could be made with careful port work and bigger valves. #5. I'd run multiple carbs, probably 4 Zenith single bbls with the thought to a blow through McCulloch supercharger. #6. I'd run a long tube header designed to work with the other stuff. #7. I'd sit down with a cam grinder and work out a cam grind that would make this package work. #8. I'd fire it with an electronic ignition. I'd make it all as old school as possible and still do what it needs to do. It's had to be specific without really knowing the Packard 8. This from a guy who has been sitting on a 413" Dodge flathead six for years.

Yeah, start with the basics, a cylinder head swap is easy enough to perform as an afterthought, once you get it going if you desire. Another thing that is often overlooked regarding many flathead style builds that will be using forced induction like this is, that while you have basically (3) choices of how to do it(turbo, roots blower or centrifugal supercharger), a turbo creates a significant heating problem for the flathead, that it doesn't in a conventional OHV engine. That might be why that historically you don't see any turbo'd flatheads, only blown or supercharged.

The fastest Flathead on the planet is Vortech powered....and its pretty awesome too!

I am with beater and cnc. The rods can't possibly be worse than a 235 rod and i have buzzed them to 6 k on a very very few occasions. And I don't ever remember hearing that packard used poor materials in their motors. Rebuild the rods and see if an arp rod bolt can be used. Good pistons, yes, you wont be sorry. Head work yes. Cam, you might consider giving Jerry Cantrel at Schneider cams in San Diego a call. He has ground my last two 261 chevy cams and was very cool to deal with and has been in the biz a long time. He should be able to sort out a grind that will work out. Unless you come across a vertex mag for the motor, I will guess that there are not to many options. I just used bubba's hot rod shop to rebuild a distributor for me. He also does custom work and is not a million dollars. He gave good advice and did a great job on my distributor so I would guess he would do the same for you.

Late to the party (just saw this).


If you are looking for a long rod that is longer than the GMC, I believe Hudson 308 rods can be an option, if rare.



That is a comparison of a 302 rod and piston, to a more modern piston with what I recall as the Hudson rod.

Gent that was building the engine claimed to remove 1 & 1/4 Lb, per hole (7 & 1/2 Lb total) with these.

I don't know how much boost I would put on them, but I wouldn't want to go over 5 Psi.

Thanks for all the interest and information. Beater you are right this is an information gathering exercise to say the least but the project will be underway fairly soon, hopefully. I will check out Schneider cams to see what they can do for me. I have an Edmunds 2X2 intake that will either accept factory Carters or a 2G style carb still deciding on which I will use but I have both on hand. The ignition option is very limited so far stock points, Pertronix electronic conversion, or Joe Hunt says they may be able to make a mag for me. I have heard that about the wide open red line of the Packard L8 is around 4,000 rpm but that could be scared guys talking (anyone have an idea on L8 RPM potential?), however I know it will likely never see the far side of 5,000 rpm. This project is really making me go back to the basics on how to make power out of an engine.

For the RPM range, typically with forced induction, the usable powerband is brought down lower than in a N/A setup for the same engine. So you might actually end up with a peak between 2500-3500 RPM. So 4000 RPM might be a realistic top out for your revs. Going any higher is just unnecessary wear and tear. Plus being a Flathead design, it will probably still be a poor breather even with porting and bigger valves, but still better than if you didn't do those mods.

I really appreciate everyone's input on this I have a lot of questions lol. I'm pretty familiar with OHV engines and how to make them work but an L8 flathead is definitely uncharted territory. I'll keep an eye out of a centrifugal supercharger, so if anyone has one that can push 7ish psi of boost and could be turned up from there with the RPM range I'm looking at let me know. From what I understand with large stroke engines that produce a lot of torque (in perspective) don't really need to rev so a 4000 RPM limit shouldn't be a problem, though transmission selection will be fun. The car has an ultramatic 2 speed (if you can really call it that) I have a couple T-5s but I don't know if they can handle the torque and heavy car combo (they are out of Fox Mustangs) I would like to go manual trans and with this engine I'm thinking an OD would be a good thing.

In respect to valves, In the OHV world my understanding id 90% or the bore diameter should be total valve diameter and of that number 60% should be intake and 40% on the exhaust does that hold true on flathead engines or is one better than the other? so 3.500 bore means total valve diameter of 2.84 (intake and exhaust diameter added together) so 1.7 for the intake valve and 1.14 on the exhaust?

On the supercharging topic if I went turbo would a factory fill in the blank turbo work for this? The engine is much larger than factory turbo engines (as far as I know) but it turns much lover RPM so I dont know if I would need a big guy or not.

The Flathead Ford commonly used 1.500" on the intake and exhaust, but had a much smaller bore than your Packard. So something in the 1.6-1.7 range might not be that unreasonable, just make sure you have enough valve seat area to go that large first. What size are the valves now.

I would have to check but they are not large nothing like a Hudson 308. Also not much meet in the block in that area so putting much larger valves would be difficult at best but just eyeballing it i would think a 1.7 would fit and I would reasonably be able to clean up the bowl area underneath. The intake ports are simiesed though so its going to be hard to increase the breathing much.

I have a Straight 8 Pontiac that i'm tinkering with making parts for, so I know what its like working with an underdog. But every little bit helps out.

Don't the heads have water cooling running thru them?

Packardkid,
I'm trying to take some measurements off the picture for a growing database so I can calculate torq/power etc.

If I scale the pic so rod length=8.5, then I get
deck height~12.3
compression height~2.5
Rod journal ~2.25 (about right)
Bore~3.5 (sounds right)
But this all puts the piston almost an inch above the deck.
I must be measuring wrong or something, maybe you have the right numbers?

Another useful thing would be to degree the stock cam before you grind it, measure valve events at say .006, .050, .100, .200 lobe lift and max lift (probably worn a bit). Modern specs like .050" lobe lift events are pretty standard now but nobody knows em on this old stuff unless we go back and measure it!

Some of the valve size issues will work themselves out under boost. When the door opens the wind will rush in. That thing turning 2500-3500 RPMs will be a beast.

For a standard OD tranny that is tough I'd consider a Borg Warner T 85 with an R 11 over drive. These were used in Studebaker Golden Hawks (supercharged 289 V8) and Ford pickups. The T 85 is what ford patterned the 4 speed "Rock Crusher" after.

When Ron Golden used the Hudson rods in his 302 GMC the gig end had to be narrowed to fit the GMC crank and the crank was ground to Mopar flat head spec so Dodge rod bearings could be used. The Hudson rods are 8". It is interesting how many old race cars used welded rods.

I pulled up some old tech manuals online to come to the 8.5 rod length it is possible that it is the wrong year or something like that. I will be pulling my spare engine down in the next couple months (I know I'm slow)so I will be able to get more accurate measurements on everything. tlowe, the heads do have water running through them. I believe Packard had the same manual OD trans (could be wrong) and I am more than OK using a vintage transmission, however with the fun I am having finding parts for and improving the strength of the engine I don't know that I want all that fun again with the transmission. I have found a company who has a bellhousing adapter for this to a modern GM transmission manual or automatic I might end up going that route. I might look into the Hudson rod option, if I can find some that is.

Slow and steady wins the build. I do believe that Packard used the BW T85. There is no stronger 3 speed OD and very few period stick trannys that can match it. If you are not into "old school" or not seeking an edge in a vintage racing class the whole Packard 8 choice seems to be folly. The T85 would be a kick to drive.

If you are bound to set this engine up against the performance of modern engines I don't think you will ever meet this goal ,"It will be in the 52 Packard club coup it came in. I would like to street drive it and I plan to do so rather often, i wont say every day but a few times a week for sure." If you have deep pockets and want to thumb your nose at a few V8s go for it.

I think a 3800ish pound car would have a hard time against anything modern, and sadly the pockets are rather shallow as well lol. But I want something fun and unique and not many people have a warmed over L8 Packard hence the appeal to me. I have had more than one person (especially Packard purists) say leave it alone and drive it in stock form but that just doesn't appeal to me. Maybe I'm the weird one lol.

You have "Hot Rod" in your veins. The coolest thing about the Studebaker Drivers Club is the attitude of most members that if it was ever a Studebaker it is still a Studebaker. The Packard guys I know are a bit more stuffy when it comes to "improved" performance. You can have a lot of fun with both the modern guys and the stuffy guys, but it must still be running when the fun is over. You don't have to out run them you just have to make them run harder and think. WTF?

Yeah "Hot Rod" for sure lol. I was on a Packard forum for a long time but they didn't really seem to like my ideas and were very against anything that was not factory. I like how you think Beater and on top of any performance modifications I don't want to blow the engine it is to rare and would be way to hard to try and replace.